The lubricating activity of synovial fluid glycoproteins

Friction measurements were performed on fractions prepared from bovine synovial fluid by using a cartilage on glass apparatus. A fraction containing lubricating glycoprotein-I (LGP-I) as the only detectable component at concentrations of 30–50 μ/ml was able to lubricate in an identical manner to whole synovial fluid. These data indicate that LGP-I is the molecule responsible for the lubricating ability of synovial fluid. ¹²⁵Iodine-labeled LGP-I also lubricated in a manner similar to synovial fluid, whereas when this sample was reduced and alkylated or treated with neuraminidase, the lubricating activity was greatly decreased. In tests to measure binding of ¹²⁵I LGP-I to cartilage, an initial linear increase in binding was observed, followed by a decrease in binding at higher concentrations. In contrast, both the reduced and alkylated and the neuraminidase treated samples did not show the same concentration-dependent binding to the cartilage. It is suggested, therefore, that at least part of the lubricating ability of LGP-I is dependent upon its ability to bind to articular cartilage.     

Psychometric properties of the MSPSS and NOS in psychiatric outpatients

Prior research has demonstrated the utility of the Multidimensional Scale of Perceived Social Support (MSPSS) and the Network Orientation Scale (NOS) as measures of perceived social support among nonpsychiatric samples. The primary objective of this study was to determine whether these two scales can be used reliably among psychiatric outpatients, in particular those with schizophrenia or a major affective disorder. Subjects were 144 outpatients, aged 21 to 67 years, who completed the MSPSS and NOS. Results demonstrated high internal consistency for the MSPSS and adequate internal consistency for the NOS. In addition, convergent validity was demonstrated. Scores on both scales for these psychiatric outpatients were found to be lower as compared to “normals”.     

THE INTRARENAL PRESSURE DURING EXPERIMENTAL RENAL HYPERTENSION

The intrarenal interstitial pressure was measured during the course of experimental renal hypertension in dogs. In perinephritic hypertension, produced by wrapping the kidney in a cellophane bag, the intrarenal pressure rose slowly from the normal value of 25 mm. Hg to a final level of about 60 mm. Hg. Strong pressure pulsations were observed in the renal parenchyma during this type of hypertension. In the hypertension following partial occlusion of the renal artery, the intrarenal pressure remained approximately normal, except in malignant hypertension when it tended to decline to about 9 mm. Hg. The hypertension of perinephritis is interpreted as a consequence of renal ischemia, the high intrarenal pressure, produced by the constricting fibrotic hull, acting to reduce the effective perfusion pressure of the kidney. The two experimental hypertensions herein examined are considered as examples of influent resistance hypertensions and effluent resistance hypertensions, the former being due to renal arterial or arteriolar resistance and the latter due to renal venous resistance, specifically at the arcuate-interlobar junction. The application of this concept to renal hypertensive disease in man is discussed.     

Observations of the temporal variation in chemical content of decomposition fluid: A preliminary study using pigs as a model system

In this paper we report the results of our preliminary studies into short chain fatty acids that have the potential to show reproducible patterns over certain postmortem intervals during decomposition in the absence of a soil matrix. Additional compounds that were detected, including several long chain fatty acids, were also investigated for their potential in estimating postmortem interval. Analysis of data was conducted to establish any distinct relationship between the levels of particular compounds produced with respect to time and temperature. Pork rashers (belly pork), whole stillborn piglets and whole adult pig (Sus scrofa) carcasses were used to model the human decomposition process in two separate locations, Western Australia (Perth) and Southern Canada (Oshawa). This enabled a comparison of components to be carried out under significantly different climatic conditions. Compounds were identified after analysis with gas-chromatography mass-spectrometry. Preliminary observations indicate that both short-chain and long-chain acids followed an apparent cyclic trend. All trials showed differences with respect to rate of decomposition, both between trials and between subjects in the same trial; however, the identity of the compounds detected for the pork rasher trial (Perth) and the pig trial (Canada) remained very similar.     

Use of the Optomap with lid retraction and its sensitivity and specificity#

Background: Optomap uses the ultra‐wide field scanning laser ophthalmoscopy to provide retinal examination. It permits fundus examination without the use of a mydriatic, which is more comfortable for the patients. This paper determines the sensitivity and specificity of the Optomap for detecting retinal signs under non‐mydriatic conditions. Methods: Fifty‐four eyes identified with retinal/choroidal signs and eight normal eyes were recruited from 31 Hong Kong Chinese subjects. Photo‐documentation of fundal changes was obtained with the Optomap under non‐mydriatic conditions before a dilated fundus examination by a clinician using standard procedures. The eyelid was retracted using a cotton bud when necessary. Dilated fundus examinations were performed by another clinician using binocular indirect ophthalmoscopy and slitlamp biomicroscopy with a fundus lens. The Optomap images were evaluated by four other investigators under masked condition. The International Classification of Disease, Ninth Revision (ICD‐9‐CM) was adopted for recording retinal features. Screening results were compared with those obtained using the dilated fundus examination as the gold standard. Results: The cotton bud method for eyelid retraction showed an improvement in the area of retina that could be visualised. The sensitivity and specificity of the Optomap averaged 76.4 and 71.9 per cent, respectively. Some fundal signs were missed by all observers in the Optomap but not with the biomicroscope. These included white‐without‐pressure, lattice degeneration, paramacular drusen and pigmentary changes at central fundus. Conclusion: Optomap serves as a reliable screening tool for fundus examination especially because it covers a much wider area of the peripheral retina than other digital instruments for fundus photography.     

Modifying rates of reductive elimination of leaving groups from indolequinone prodrugs: a key factor in controlling hypoxia-selective drug release

3-(4-Methylcoumarin-7-yloxy)methylindole-4,7-diones were synthesised as model prodrugs in order to investigate the correlation between rates of reductive elimination from the (indolyl-3-yl)methyl position with reductive metabolism by hypoxic tumor cells and NADPH: cytochrome P450. Rates of elimination of the chromophore/fluorophore (7-hydroxy-4-methylcoumarin) following one-electron reduction of indolequinones to their semiquinone radicals (Q*-) was measured by pulse radiolysis utilising spectrophotometric and fluorometric detection. Incorporation of a thienyl or methyl substituent at the (indol-3-yl)CHR-position (where R=thienyl or methyl adjacent to the phenolic ether linking bond) significantly shortened the half-life of reductive elimination from 87 to 6 and 2 ms, respectively. Elimination from the methyl substituted analogue can thus compete effectively with the reaction of the semiquinone radical with oxygen at levels typically present in tumours (half-life approximately 1.8 ms at 0.5% O2). Chemical kinetic predictions were confirmed by metabolism in breast tumour MCF-7 cells between 0-2.1% O2. Rates of reductive release of the fluorophore from the non-fluorescent parent indolequinones (R=H, Me, thienyl) were similar under anoxia ( approximately 1.7 nmol coumarinmin(-1)mg protein(-1)) reflecting the similarity in one-electron reduction potential. Whereas coumarin release from the indolequinone (R=H) was completely inhibited above 0.5% O2, the enhanced rate of reductive elimination when R=thienyl or Me increased the metabolic rate of release to approximately 0.35 and 0.7 nmol coumarinmin(-1)mg protein(-1), respectively at 0.5% O2; complete inhibition occurring by 2.1% O2. Similar 'oxygen profiles' of release were observed with NADPH: cytochrome P450 reductase. In conclusion, it is possible to modify rates of reductive elimination from indolequinones to control the release of drugs over a range of tumour hypoxia.     

Collaborative investigation of an outbreak of Salmonella enterica serotype Newport in England and Wales in 2001 associated with ready-to-eat salad vegetables

In June 2001, as part of a microbiological study of bagged, ready-to-eat salad products, Salmonella enterica serotype Newport was isolated from a sample of pre-packed green salad distributed by a major supermarket retailer. The strain was characterised by phage typing, plasmid profile typing and pulsed-field gel electrophoresis. Other isolates of S. Newport from cases of human infection in England and Wales in the first six months of 2001 were similarly characterised. Of 60 strains from cases of human infection, 19 were found to be indistinguishable from that isolated from the salad product. This study highlights the benefits of an integrated approach to outbreak investigations, involving the various elements of the PHLS and the Food Standards Agency, and acknowledges the full co-operation of the retailer in ensuring the rapid withdrawal of the contaminated product.     

Localized epidermolytic hyperkeratosis of the female external genitalia

BACKGROUND: Epidermolytic hyperkeratosis (EH) is most commonly associated with the diffuse involvement of congenital ichthyosiform erythroderma, but can also be found in a localized pattern. Localized EH is rare, but mucocutaneous lesions have been been identified, most commonly in the mouth. METHODS: We observed a 58-year-old African-American female who noted spots on her genitalia for approximately 2 years. The lesions were increasing in size, darkening, and had become pruritic and sore over the past 6 months. RESULTS: Physical examination revealed seven scattered, tan to brown, verrucoid papules on the labia and mons pubis, resembling condylomata acuminata or Bowenoid papulosis. Biopsy of a single labial papule revealed epidermal acanthosis, compact hyperkeratotic papillomatosis, perinuclear clear zones, granular keratohyalin clumping, hypergranulosis, and dyskeratosis resulting in intracellular eosinophilic globules, all characteristic of EH. CONCLUSIONS: Because of the rarity of localized genital EH and similar appearance to common diagnoses, clinical confusion may occur without biopsy.